Question 1: Calculate the area of a circle with a radius of 5 cm.

Answer: 78.54

Question 2: A circle has an area of 50.24 cm². Find its radius, rounded to two decimal places.

Answer: 4

Question 3: A circular garden has a diameter of 10 m. Calculate its area.

Answer: 78.54

Question 4: Construct a circle with an area of 150 cm². What should be the radius? Show your working.

Answer: 6.93

Question 5: A wheel has an radius of 0.5 meters. Calculate the area of its face.

Answer: 0.785

Question 6: Calculate the area of a circle with radius 12 cm.

Answer: 452.39

Question 7: A circular pond has an area of 314.16 m². What is its radius?

Answer: 10

Question 8: A circular track has a radius of 100 meters. Calculate its area in hectares (1 hectare = 10,000 m²).

Answer: 3.14

Question 9: A frisbee has a radius of 8.5 inches. Calculate its face area in square inches.

Answer: 227.02

Question 10: Error Analysis: A student calculated the area of a circle with radius 7 cm as 154 cm², claiming π≈3.14. Is this correct? If not, identify and correct the mistake.

Answer: No. Using π≈3.14, the area should be 3.14×7²=3.14×49=153.86 cm², which is close but slightly different. The student rounded π incorrectly or used a different value. The correct answer is approximately 153.86 cm².